Water-dispersible polymers, particularly sulfopolyester polymers, are used in the formation of fibers and fibrous articles such as non-woven fabric, bicomponent fibers, films, clothing articles, personal care products such as wipes, feminine hygiene products, diapers, adult incontinence briefs, hospital/surgical and other medical disposables, protective fabrics and layers, geotextiles, industrial wipes, and filter media. Oftentimes, many of these items are washed during the course of their manufacture or use. As a result, significant quantities of the sulfopolyester polymers become liberated from the articles and dispersed in the wash water.
For example, multicomponent fibers comprising a water-dispersible sulfopolyester and a water non-dispersible polymer, such as polyester, nylon or polyolefins, can be used in the manufacture of microdenier fibers and microdenier fiber webs. These fibers have been described, for example, in U.S. Pat. Nos. 6,989,193, 7,902,094, 7,892,993, and 8,513,147. The multicomponent fibers can be laid into a non-woven web which may be transformed into a microdenier fiber web by removing the sulfopolyester component of the fibers. This is most commonly accomplished by washing the web thereby causing the sulfopolyester to disassociate from the multicomponent fibers from which the web is made. The disassociated sulfopolyester becomes dispersed in the wash water.
The sulfopolyester dispersion is generally very dilute exhibiting only a very modest concentration of sulfopolyester. Heretofore, the sulfopolyester present in the wash water has been considered to be of little economic value and is typically discarded along with the wash water. Accordingly, there is a need for an economically viable and efficient method for concentrating and/or recovering the sulfopolyester from the wash water for subsequent reuse.